1. Field of the Invention
This invention relates to vehicle pneumatic suspension systems, specifically a pneumatic suspension system dampener which promotes absorption of high impulse road shocks and vibrations and promotes a smoother ride when driving over rough road conditions.
2. Description of the Prior Art
Pneumatic suspension systems are not novel, but associated system dampeners are. Conventional pneumatic suspension systems include pneumatic suspension elements, typically variable-volume chambers, mounted between the vehicle's wheel assemblies and chassis, which are pressurized by a compressor via fluid conduit. When a vehicle's wheel assembly experiences rough road conditions, shocks and vibrations are imparted to its pneumatic suspension elements which compress the gas contained therein. Gas compression is limited to a critical point where forces generated by inertia and vehicle weight are equal to or less than the gas pressure within the elements, referred to herein as "bottoming out." When a pneumatic suspension element has bottomed out, any additional force transmitted to the element will be substantially transmitted to the vehicle, passengers and cargo. Conventional systems, unlike the present invention, fail to provide vehicle passengers and cargo relief from road shocks which may lead to passenger injury and/or cargo damage.
The prior art encompasses different configurations of pneumatic suspension systems.
U.S. Pat. No. 2,971,772 issued Feb. 14, 1961 to K. W. Tantlinger et al. describes a suspension system comprising dual variable-volume chambers symmetrically mounted about an axle of the vehicle on a member pivotally mounted to the axle such that the member may see-saw about the axle. Tantlinger's invention fails to provide a means to relieve the suspension system's pneumatic elements of the impulses which are ordinarily transmitted to the vehicle passengers and cargo when the suspension elements bottom out.
U.S. Pat. No. 2,984,501 issued May 16, 1961 to P. E. Mercier describes a suspension system comprising a piston which pumps liquid from a cylinder into: (1) in cases where pumping is slow, a resilient toroidal chamber containing an adjustably gas-pressurized toroidal variable-volume chamber; or (2) in cases where pumping is rapid, a significantly larger hemispherical chamber containing an adjustably gas-pressurized hemispherical variable-volume chamber. Although Mercier's invention does include a biased damper in series with pneumatic variable-volume chambers for shock absorption as in the present invention, Mercer's invention focusses on absorbing shocks directly from the wheel assembly rather than relieving the suspension system's pneumatic elements of the impulses which are ordinarily transmitted to the vehicle passengers and cargo when the suspension elements bottom out. Additionally Mercier's invention is not in communication with the pneumatic suspension system.
U.S. Pat. No. 3,148,871 issued Sep. 15, 1964 to D. B. Wilkins et al. describes a suspension system comprising a piston which pumps liquid from a cylinder into the first half of a chamber which has a membrane separating the liquid from pressurized gas stored in the second half of the chamber. U.S. Pat. No. 3,149,830 issued Sep. 22, 1964 to R. J. Broadwell describes a similar suspension system comprising a piston which pumps liquid from a cylinder into the cylinder jacket which has an opened end which is sealed by a folding seal which separates the liquid from a chamber charged with air. As with Mercier's invention above, Wilkins' and Broadwell's inventions do not relieve the suspension system's pneumatic elements of the impulses which are ordinarily transmitted to the vehicle passengers and cargo when the suspension elements bottom out and do not tie into the pneumatic suspension system.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.